JPH0710324A - Paper-carrying and aligning device for copying machine, etc. - Google Patents

Abstract

PURPOSE: To prevent clogging of a paper sheet by inserting the sheet between register rollers in a state where the paper sheet is perfectly aligned in the proceeding direction on a copying machine etc. CONSTITUTION: A paper sheet carrier and alignment device of a copying machine etc., receives paper sheets from a plural number of different cassettes 14 and delivers these sheets to register means 32, 34. The sheets proceed toward the register means through a common passage 54. These register means are a pair of the rollers 32, 34 at least one of which is a metallic roller. The sheets at first make contact with this metallic roller, slide toward a registration range between the two rollers, and hereby the sheets are oriented toward the metallic roller so that the sheets are precisely aligned.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet conveying and aligning apparatus particularly suitable for a laser printer, an electrophotographic copying machine or other similar office equipment.

More specifically, the present invention registers sheets fed selectively from multiple directions in a manner such that each sheet is accurately positioned in the direction of travel with respect to the aligning or aligning rollers. The present invention relates to a device for transporting to a (alignment roller) or a sheet alignment roller.

[0003]

2. Description of the Prior Art U.S. Pat. No. 4,403,851 selects sheets from different stacks of sheets, such as in conventional first and second cassettes, each cassette containing about 250 sheets. And a large cassette that is placed below the copier and holds about 1,000 sheets, and also as a "bypass" for manually inserting one sheet at a time. A copier with a known path is disclosed. The paper is conveyed along three paths that all reach the area immediately upstream of the pair of registration rollers.

[0004]

However, such copiers do not employ any means for accurately positioning the sheets arriving from any of the various sheet stacks between the aligning rollers. Therefore, a certain sheet may be inserted between the aligning rollers without being perfectly aligned in the traveling direction, which causes jamming of the sheet.

[0005]

The present invention comprises various features described in the claims.

The preferred embodiment provides an apparatus for transporting sheets arriving from different sheet stacks or different directions to an alignment roller to align the sheets. A feeder removes the sheets from the cassette and feeds the sheets along a feed path to a common aligner. There is a common path for the paper to advance towards a metal roller in the registration area, which common path is arranged towards this metal roller. The paper slides freely against the metal roller. Therefore, the paper is precisely and naturally aligned between the metal roller and the adjacent roller against which the metal roller presses.

The adjacent rollers are preferably made of rubber.

[0008]

The features of the present invention will become more apparent from the following detailed description of a preferred embodiment, given by way of non-limiting example only, with reference to the accompanying drawings.

Referring to FIG. 1, the sheet transport apparatus according to the present invention is installed in a laser printer 10, for example.
It should be appreciated that the paper transport can be attached to either an electrophotographic copier or any office information processing device that prints information on paper arriving from different paper stacks.

In most cases, the information to be printed is in the form of an image and / or a text input by a writing means or an input device of a personal computer or a keyboard. Although these means are not shown in the drawing, they can be connected to the printer via a cable.

The printer 10 includes a main cassette 14 disposed in the printer 10, or a suitable device 17 disposed below the printer 10 and functioning as a paper support.
The sheets 12 accommodated in any of the auxiliary cassettes 15 (FIG. 4) accommodated therein are selectively supplied. The paper can also be manually fed through the slot 18 on the left side of the printer 10 (FIG. 1).

The printer 10 is a developing device D of a known type.
U, and the developing unit DU is a logical processing unit L
The information supplied by U and sent to the developing device DU by the laser beam LR emitted by the laser generator LG is developed using toner. The developed information is transferred to each sheet in the transfer station TS facing the developing device DU. The paper 12 then advances through a fusing station FU formed from two fusing rollers 80, 81 that utilize heat to fuse the toner particles to the paper. After the fixing process, the paper advances along the guide 83, and then is conveyed by the roller R into the paper discharge tray T at the top of the printer.

After opening the door 23, the cassette 14 can be taken out and refilled with new paper through the opening 22 on the left side of FIG.

The sheets 12 may be removed from the cassette 14 one at a time by a clockwise rotating sheet separating roller 24, which may interact with the friction block 25 and adhere to the desired sheet 12. Block the passage of the second sheet with the sheet. The separation roller 24 is attached to an auxiliary frame 26 that is hinged to the printer structure at points 27. The auxiliary frame 26 has an arrow 2
It pivots upward in the direction of 8 to allow the cassette 14 to be taken out.

At the downstream side of the separating roller 24, the sheet 12 pushed by the separating roller 24 is curved upward toward the pair of aligning rollers 32 and 34, and in front of the developing unit DU in the advancing direction of the sheet. First a short distance from
Enter passage 30.

The alignment roller 32 is made of a flexible rubber sheet 35.
While the alignment roller 34 is formed of polished steel. These pair of alignment rollers 32, 34
Press against each other to define an alignment or contact area and introduce the leading edge of the paper into this area to align the paper accurately in the direction of travel.

These aligning rollers 32 and 34 are normally stationary, and can be rotated after the paper is inserted into the alignment area to advance the sheet 12 toward the developing device DU. When information is to be printed by hand on the paper 12 'inserted in the slot 18, the paper 12' is manually pressed against a pair of rotatable rollers 36, 37 that press against each other. The roller 36 is started by its own electric motor 38,
On the other hand, the roller 37 runs idle. Sensor 40 is roller 3
The printer 1 is arranged immediately before the contact points of 6 and 37.
Signals the presence of the paper 12 'to the logic unit LCU which controls all the functions that 0 should perform.

When the sheet 12 'is inserted into the slot 18, the logic unit LCU always starts the motor 38 for a short time, based on the signal from the sensor 40, so that the sheet contacts the rollers 36, 37. Through a small distance, for example 20 mm. Next, the motor 3
8 is stopped and paper 12 'is held stationary until the operator presses a button (not shown) to initiate the print cycle.

In this way, there is no need for the operator or to support the paper 12 'with protruding brackets, and the absence of such brackets allows the size of the printer to be reduced.

When the operator presses the cycle start button, the motor 38 is restarted and the paper 12 'is moved to the rollers 32, 34.
These alignment rollers 32, 34 are advanced through a second passage 44 that curves upwardly toward.

On the other hand, when the auxiliary cassette 15 under the printer 10 is used (FIG. 4), the paper 12 ″ accommodated in the cassette 15 and having a different style from the paper in the main cassette 14 has the paper separating roller 45 and A pair of advancing rollers 47 (FIG. 1) feeds the alignment rollers 32, 34. The rollers 47 delimit the third passage 5 bounded by the outer surfaces of the guides 51 and the protrusions 52 of the cassette 14.
Press the paper 12 ″ along the 0 (FIG. 1).
0 joins the second passage 44 downstream of the roller 36. The first and second passages 30,44 arrive from two generally opposite directions and merge into a single passage 54 which is relative to the first and second passage directions. The contact areas of the rollers 32 and 34 are reached in a substantially vertical direction.

The single passages 54 (FIG. 2) each have a first
Is bounded by two ends 55, 56 of two walls or guides 57, 58 that delimit the passage 30 and the second passage 44 of. On the other hand, the first and second passages 30, 4
4 are separated by a portion 60 having a generally triangular cross section and having an apex 62 at the lower portion 63 of a single passage 54. Separation portion 60 defines a boundary with passage 30 by a curved wall 64 that biases the leading edge 65 of the sheet pressed by sheet separation roller 24 to provide a single passage 54.
Slide toward.

This sliding occurs when the incident angle "α" between the traveling direction of the sheet 12 and the tangent line 66 of the guide at the contact point of the leading edge 65 of the sheet is smaller than the critical angle of about 40 °. It is known to be done accurately without sticking.

Therefore, in order to satisfy this condition, the block 25 is moved at an angle "β" of about 25 ° at an angle to the rotation direction of the roller 24, and the paper 12 is incident at an incident angle smaller than 40 °. Sliding above wall 64. Next, the paper 12 is curved projection 48 from the frame 26.
And guided by a wall 57, move above the first passage 30 and enter a single passage 54.

During this feeding stage of the paper 12, 12 'or 12 ", the alignment rollers 32, 34 are stationary and then the paper 1
In order to avoid the front end of the 2, 12 ', 12 "contacting the rubber roller 32, the single passage 54 has a steel roller 34
In the direction of. The reason is that if the leading edge of the paper contacts the alignment rubber roller 32 before it reaches the alignment or contact area between the alignment rollers 32, 34, the paper 12 will be misaligned with its direction of travel, causing a paper jam. Because. On the other hand, if the leading edge of the paper 12 first contacts the steel roller, the paper 12 slides on its roller surface and is fed exactly into the registration area between the registration rollers 32, 34. In this way, the paper 12 is accurately aligned with the direction of travel when further pressed by the paper separating roller 24. As shown in FIG. 3, the wall 56 is a steel roller 3
Since it is inclined toward 4, the imaginary protrusion 70 on the inner surface 71 passes a position “b” from the contact or alignment area between the alignment rollers 32, 34.

This distance "b" is 1 to 2 mm,
Measured along the radius "R" of the alignment roller 34 through the alignment area.

The walls 55, 56 may be parallel to each other, but converge upwardly at a convergence angle "γ" of 4 ° to 6 ° with a gap between them having a width of 0.8 to 1.2 mm. It is desirable to form the outlet slot 74.

Between the aligning rollers 32 and 34, each paper 12,
In order to optimally introduce the 12 'or 12 "leading edge,
The distance "c" between the apex 62 of the portion 60 and the straight line connecting the axes A1, A2 of the pair of aligning rollers 32, 34 is
While having a length of 13 to 18 mm, the length "l" of the single passage 54 should be 8 mm or more. In any case, the distance "d" between the leading edge 56 'of the wall 56 and the roller 34 should not be less than 1.5 mm.

A pair of aligning rollers 36, 37 (FIG. 2)
Are arranged so that the paper 12 'can be pushed in the upward tilt direction at an angle "δ" of about 15 °, so that the leading edge 77 does not stick and the wall 78 of the part 60 is not attached. Slide up. The alignment rollers 36 and 37 are the paper 12 '.
Through the passage 54 along the wall 78 and finally up the steel roller 34. At this point, the leading edge 77 of the paper 12 'is fed between the fixed alignment rollers 32,34,
In this position, the sheet 12 is accurately positioned by the pressing force from the aligning rollers 36 and 37 in the same manner as described above. As mentioned above, the station TS
The toner particles transferred to one side of the paper 12 in (FIG. 1) are fixed to the paper by utilizing heat by the two rotating rollers 80 and 81 which press the paper 12 against each other.

The rotating roller 80 is made of rubber and contacts the back side of the paper. The rotating roller 80 is made of Teflon-coated metal (MR) and is heated to about 180 ° C.

The sheet coming out of the fixing station FU is then advanced to the sheet discharge tray T by the guide 83 and the roller R.

It will be appreciated that variations, additions or substitutions of the components of the paper transport apparatus described above are possible without departing from the scope of the invention.

[Brief description of drawings]

FIG. 1 is a schematic view of a laser printer that uses a sheet transport device according to the present invention.

FIG. 2 is a diagram of a conveyance and alignment device of the sheet conveyance device of FIG.

FIG. 3 is an enlarged detail view of the apparatus of FIG.

FIG. 4 is a schematic view showing an arrangement of auxiliary paper cassettes for the printer of FIG.

[Explanation of symbols]

10 Laser Printer 12 Paper 14 Cassette 15 Auxiliary Cassette 18 Slot 22 Opening 23 Door 24 Separation Roller 25 Friction Block 26 Auxiliary Frame 28 Arrow 30 Passage 32 Alignment Roller 34 Alignment Roller 35 Rubber Sheet 36 Roller 37 Roller 38 Electric Motor 40 Sensor 44 Passage 45 Separation Roller 47 Forward Roller 50 Passage 51 Guide 52 Protrusion 54 Passage 55 Wall 56 Wall 57 Guide 58 Guide 60 Cross Section 62 Vertex 64 Curved Wall 65 Leading Edge 78 Curved Wall 80 Fusing Roller 81 Fusing Roller 83 Guide DU Developing Device FU Fixing station LCU Logic unit LG Laser generator LR Laser beam LU Logic processor T Paper ejection tray TS Transfer station R Roller

Front page continuation (72) Inventor Riccardo Forlani Italy 10146 Turin, Corso Bernardino Teresio 40

Claims (12)

[Claims] 1. Container means (14, 15) for accommodating a plurality of sheets (12), and removing said sheets from each of said container means, and aligning said sheets along at least one passage (30). A plurality of feeding devices (24, 45) for advancing to 32, 34) and at least one sheet of paper,
An additional introduction device (36, 37) for advancing the sheet to the aligning means along a second path oriented in a direction different from the direction of the first path, the aligning means comprising: An apparatus for transporting and aligning a sheet, comprising at least one metal roller (34) defining an alignment area, wherein the first and second passages (30, 44) are substantially aligned with the alignment metal roller (34). ) Converges towards a common passageway (54) oriented towards (4) to ensure that the paper (12) is correctly inserted into the alignment area in alignment with the direction of travel of the paper. A device characterized in that 2. A device for conveying and aligning sheets according to claim 1, wherein said first and second passages (30, 4) are provided.
4) is a portion (60) of triangular cross section having an apex (62) at one end of the common passage, bounded by first and second curved walls (64, 78) sharing the apex. Device characterized by being separated by a portion (60) defined. 3. An apparatus for transporting and aligning sheets according to claim 1 or 2, wherein the first passage includes:
Directing in a direction substantially opposite to the direction of the second passage, the common passage (54) being oriented in a direction substantially perpendicular to the first and second passages. Characterized device. 4. An apparatus for transporting and aligning sheets according to claim 1, wherein the common passage (5) is provided.
4) is bounded by two flat walls (55, 56), an imaginary projection of one of said walls being located at a distance (b) of 1 to 2 mm from said alignment area to said metal roller ( 34) A device characterized by passing towards. 5. An apparatus for transporting and aligning paper according to claim 4, wherein the distance is measured along a radius of the roller passing through the alignment area. 6. A device for transporting and aligning sheets according to claim 4 or 5, wherein said two flat walls (55,
A device characterized in that 56) are parallel. 7. A device for transporting and aligning sheets according to claim 4 or 5, characterized in that the two flat walls converge with each other at a convergence angle in the range of 4 ° to 6 °. And the device. 8. A device for transporting and aligning sheets according to claim 1, wherein the common passage has a length of 8 mm or more. 9. A device for transporting and aligning sheets according to claim 2, wherein the feeding device is associated with a feeding roller (24).
5), wherein the separation block (25) causes the feed roller to press the sheet of paper against the first curved wall (64) at an angle of incidence α less than a predetermined critical value,
Device characterized in that it is oriented with respect to said feed roller (24). 10. An apparatus for conveying and aligning a sheet according to claim 2, wherein the sheet introduction device is pressed against the second curved wall at an incident angle at which the sheet is smaller than the critical value. A device comprising a pair of rollers oriented as described above. 11. An apparatus for transporting and aligning a sheet according to claim 9 or 10, wherein the incident angle has a critical value of about 40 °, and the leading edge of the sheet does not adhere to the first sheet. A device characterized by ensuring free sliding over the first and second curved walls. 12. A device for transporting and aligning paper according to claim 10, wherein the paper introducing device holds the paper manually inserted between the oriented rollers until a print cycle begins. A device characterized by: